Semiconductor device and method of fabricating the same

ABSTRACT

Provided herein may be a semiconductor device and a method of manufacturing the same. The semiconductor device may include a memory string including memory cells coupled to each other in series via a channel layer, the memory string coupled between a bit line and a second source line. The semiconductor device may include a first source line electrically coupled to the second source line through the channel layer.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 15/972,395, filed on May 7, 2018, and claimspriority under 35 U.S.C. § 119(a) to Korean patent application number10-2017-0123410 filed on Sep. 25, 2017 in the Korean IntellectualProperty Office, the entire disclosure of which is incorporated hereinby reference.

BACKGROUND 1. Technical Field

Various embodiments of the present disclosure generally relate to asemiconductor device and a method of fabricating the same, and moreparticularly, to a three-dimensional semiconductor memory device and amethod of fabricating the same.

2. Related Art

A semiconductor device includes a plurality of memory cell transistorscapable of storing data. The memory cell transistors may be coupled inseries between select transistors, thus forming a memory string. Toembody high integration of a semiconductor device, a three-dimensionalsemiconductor device has been proposed. Gate electrodes of the memorycell transistors and the select transistors may be stacked on asubstrate to form the three-dimensional semiconductor device. Thethree-dimensional semiconductor device further includes a channel layerpassing through the gate electrodes. With regard to the realization ofsuch a three-dimensional semiconductor device, various techniques forimproving the operational reliability of the semiconductor device arebeing developed.

SUMMARY

An embodiment of the present disclosure may provide for a semiconductordevice. The semiconductor device may include a well plate. Thesemiconductor device may include a separation layer disposed on the wellplate. The semiconductor device may include an auxiliary source linelayer disposed on the separation layer and spaced apart from the wellplate. The semiconductor device may include a stack structure formed onthe auxiliary source line layer. The semiconductor device may includechannel layers configured to pass through the stack structure, andelectrically coupled to the well plate and the auxiliary source linelayer.

An embodiment of the present disclosure may provide for a method ofmanufacturing a semiconductor device. The method may includesuccessively stacking and forming, on a semiconductor substrate, a firstconductive layer for a first source line, a separation layer, asacrificial layer, an etch stop layer and a plurality of first andsecond material layers. The method may include etching the firstmaterial layers, the second material layers, the etch stop layer, thesacrificial layer and the separation layer and forming a plurality ofchannel holes through which portions of the first conductive layer areexposed. The method may include forming channel plugs by successivelystacking a multilayer layer and a channel layer on inner sidewalls ofthe channel holes. The method may include etching a bottom of each ofthe channel holes to expose the first conductive layer, and additionallyforming the channel layer on the bottom of each of the channel holessuch that the first conductive layer comes into contact with the channellayer. The method may include etching the first material layers, thesecond material layers, the etch stop layer and forming a second sourcecontact hole through which the sacrificial layer is exposed. The methodmay include exposing a portion of a sidewall of a lower portion of eachof the channel plugs by removing the exposed sacrificial layer. Themethod may include exposing a portion of the channel layer by removingthe multilayer layer of the exposed lower portion of each of the channelplugs, and filling a region from which the sacrificial layer has beenremoved with a second conductive layer for a second source line suchthat the second conductive layer comes into contact with the channellayer.

An embodiment of the present disclosure may provide for a semiconductordevice. The semiconductor device may include a memory string includingmemory cells coupled to each other in series via a channel layer, thememory string coupled between a bit line and a second source line. Thesemiconductor device may include a first source line electricallycoupled to the second source line through the channel layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating memory strings of asemiconductor device in accordance with an embodiment of the presentdisclosure.

FIG. 2 is a circuit diagram illustrating memory strings of asemiconductor device in accordance with an embodiment of the presentdisclosure.

FIGS. 3A to 3H are sectional views illustrating a method ofmanufacturing a semiconductor device in accordance with an embodiment ofthe present disclosure.

FIG. 4 is a block diagram illustrating a memory system including asemiconductor device in accordance with an embodiment of the presentdisclosure.

FIG. 5 is a block diagram illustrating an example of application of thememory system of FIG. 4.

FIG. 6 is a block diagram illustrating a computing system including thememory system illustrated with reference to FIG. 5.

DETAILED DESCRIPTION

Examples of embodiments will now be described hereinafter with referenceto the accompanying drawings; however, they may be embodied in differentforms and should not be construed as limited to the embodiments setforth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the examples of the embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.

Hereinafter, embodiments will be described with reference to theaccompanying drawings. Embodiments are described herein with referenceto cross-sectional illustrations that are schematic illustrations ofembodiments (and intermediate structures). As such, variations from theshapes of the illustrations as a result, for example, of manufacturingtechniques and/or tolerances, are to be expected. Thus, embodimentsshould not be construed as limited to the particular shapes of regionsillustrated herein but may include deviations in shapes that result, forexample, from manufacturing. In the drawings, lengths and sizes oflayers and regions may be exaggerated for clarity. Like referencenumerals in the drawings denote like elements.

Terms such as “first” and “second” may be used to describe variouscomponents, but they should not limit the various components. Thoseterms are only used for the purpose of differentiating a component fromother components. For example, a first component may be referred to as asecond component, and a second component may be referred to as a firstcomponent and so forth without departing from the spirit and scope ofthe present disclosure. Furthermore, “and/or” may include any one of ora combination of the components mentioned.

Furthermore, a singular form may include a plural from as long as it isnot specifically mentioned in a sentence. Furthermore,“include/comprise” or “including/comprising” used in the specificationrepresents that one or more components, steps, operations, and elementsexist or are added.

Furthermore, unless defined otherwise, all the terms used in thisspecification including technical and scientific terms have the samemeanings as would be generally understood by those skilled in therelated art. The terms defined in generally used dictionaries should beconstrued as having the same meanings as would be construed in thecontext of the related art, and unless clearly defined otherwise in thisspecification, should not be construed as having idealistic or overlyformal meanings.

It is also noted that in this specification, “connected/coupled” refersto one component not only directly coupling another component but alsoindirectly coupling another component through an intermediate component.On the other hand, “directly connected/directly coupled” refers to onecomponent directly coupling another component without an intermediatecomponent.

Various embodiments of the present disclosure may be directed to athree-dimensional semiconductor device which has improved operationalreliability, and a method of fabricating the same.

FIG. 1 is a perspective view illustrating memory strings of asemiconductor device in accordance with an embodiment of the presentdisclosure. Referring to FIG. 1, to schematically illustrate thestructure of the semiconductor device according to an embodiment of thepresent disclosure, the illustration of interlayer insulating layers hasbeen omitted.

The semiconductor device according to an embodiment of the presentdisclosure may include a three-dimensional memory string String. Thethree-dimensional memory string String may have a straight type, asillustrated in FIG. 1.

A straight memory string String may include memory cells and selecttransistors which are stacked along a straight channel layer CH. Gatesof the memory cells and gates of the select transistors may be coupledto conductive patterns CP1 to Cpn.

The channel layer CH may be formed in the form of a tube which enclosesan insulating pillar with which a central region of a straight hole isfilled, or may be formed such that the central region of the straighttype hole is completely filled therewith.

An upper end of the channel layer CH may be electrically coupled to acorresponding one of bit lines BL1 to BL5. In an embodiment, there isillustrated five bit lines, but the present disclosure is not limitedthereto, and more or less bit lines may be disposed. The bit lines BL1to BL5 may extend in a second direction II. A drain contact plug (notillustrated) may be further formed between each of the bit lines BL1 toBL5 and the corresponding channel layer CH.

Channel layers CH may be substantially parallel to each other and eachmay be coupled to a well plate SL1 and an auxiliary source line layerSL2. The well plate SL1 and the auxiliary source line layer SL2 may berespectively defined as a first source line layer and a second sourceline layer. The first source line layer SL1 may be formed on asemiconductor substrate, and the second source line layer SL2 may beformed over the first source line layer SL1. A separation layer SP isformed at the interface between the first source line layer SL1 and thesecond source line layer SL2 and electrically and physically separatesthe first source line layer SL1 from the second source line layer SL2. Aside surface of a lower end of each channel layer CH may be coupled tothe second source line layer SL2, and the bottom of the lower end of thechannel layer CH may be coupled to the first source line layer SL1. Thechannel layer CH may pass through the second source line layer SL2 andbe coupled to the first source line layer SL1. In other words, thesecond source line layer SL2 may enclose the channel layer CH.

The first source line layer SL1 may be formed of a doped polysiliconlayer doped with a P-type impurity. The second source line layer SL2 maybe formed of an undoped polysilicon layer or a doped polysilicon layerdoped with an N-type impurity. The lower end of the channel layer CH maybe coupled to the first source line layer SL1 and the second source linelayer SL2, and extend in a third direction III toward the bit lines BL1to BL5.

Although not illustrated, the first source line layer SL1 and the secondsource line layer SL2 may be respectively coupled to a first sourcecontact plug and a second source contact plug and thus may berespectively coupled to a first common source line and a second commonsource line. In other words, the first source line layer SL1 and thesecond source line layer SL2 may be respectively coupled to the firstcommon source line and the second common source line that areelectrically separated from each other.

A side surface of the channel layer CH may be generally enclosed by amultilayer layer ML. In an embodiment, for example, a side surface ofthe channel layer CH may be enclosed by first and second multilayerpatterns ML1 and ML2. In an embodiment, for example, a side surface ofthe channel layer CH may be enclosed by one or more multiplayerpatterns. The portion of the channel layer CH that comes into contactwith the second source line layer SL2 may not be enclosed by amultilayer layer, whereby the channel layer CH may come into directcontact with the second source line layer SL2.

An outer surface of the channel layer CH may be enclosed by the firstmultilayer pattern ML1, or be enclosed by the second multilayer patternML2. Each of the first multilayer pattern ML1 and the second multilayerpattern ML2 may include a tunnel insulating layer, a data storage layerand a blocking insulating layer. The first multilayer pattern ML1 isformed to enclose a side surface of a portion of the channel layer CHover the portion of the channel layer CH that comes into contact withthe second source line layer SL2. The second multilayer pattern ML2 isformed to enclose a side surface of a portion of the channel layer CHunder the portion of the channel layer CH that comes into contact withthe second source line layer SL2. The first multilayer pattern ML1 andthe second multilayer pattern ML2 may be separated from each other withthe second source line layer SL2 interposed therebetween.

The conductive patterns CP1 to CPn may be disposed in n layers spacedapart from each other between the bit lines BL1 to BL5 and the secondsource line layer SL2. The conductive patterns CP1 to CPn may enclosethe channel layer CH and be stacked and spaced apart from each other.The conductive patterns CP1 to CPn may include a source select line SSL,word lines WL and a drain select line DSL. The source select line SSLmay be disposed over the second source line layer SL2. The word lines WLmay be disposed over the source select line SSL. The drain select lineDSL may be disposed over the word lines WL. The conductive patterns CP1to CPn may be separated into a plurality of sub-structures by a slit SI.

The source select line SSL may be disposed to have a single layered ortwo or more layered structure below the word lines WL. Although, in thedrawing, there is illustrated an example in which the source select lineSSL is formed both of a first pattern CP1 that is disposed in alowermost layer of the conductive patterns CP1 to CPn and of a secondpattern CP2 disposed over the first pattern CP1, the present disclosureis not limited to this.

The drain select line DSL may be disposed to have a single layered ortwo or more layered structure over the word lines WL. Although, in thedrawing, there is illustrated an example in which the drain select lineDSL is formed both of an n-th pattern CPn that is disposed in anuppermost layer of the conductive patterns CP1 to CPn and of an n−1-thpattern CPn−1 disposed below the n-th pattern CPn, the presentdisclosure is not limited to this.

The conductive patterns CP1 to CPn may be separated from each other bythe slit SI. Either the source select line SSL or the drain select lineDSL may be separated into unit lines smaller than that of the word linesWL. For example, the channel layers CH that are enclosed in common byeach word line WL may be separated into a first group and a second groupwhich are respectively enclosed by drain select lines DSL that areseparated from each other. In this case, the drain select line DSL maybe separated not only by the slit SI but also by an upper slit USI sothat the width thereof is less than that of each of the word lines WL.

The memory cells are formed at intersections between the channel layerCH and the word lines WL, a drain select transistor is formed at anintersection between the channel layer CH and the drain select line DSL,and a source select transistor is formed at an intersection between thechannel layer CH and the source select line SSL. The source selecttransistor, the memory cells and the drain select transistor that arearranged in a line along the single channel layer CH are coupled inseries to each other through the channel layer CH and thus define astraight memory string String. The word lines WL may transmit signals tothe gates of the memory cells. The source select line SSL may transmit asignal to a gate of the source select transistor. The drain select lineDSL may transmit a signal to a gate of the drain select transistor.

FIG. 2 is a circuit diagram illustrating memory strings of asemiconductor device in accordance with an embodiment of the presentdisclosure.

Referring to FIG. 2, the semiconductor device according to an embodimentof the present disclosure may include a memory cell array 100 having athree-dimensional structure. The memory cell array 100 includes aplurality of memory strings String. Each of the memory strings Stringmay include a source select transistor SST, a plurality of memory celltransistors MC1 to MCn and a drain select transistor DST that arecoupled in series to each other. The number of source select transistorsSST or the number of drain select transistors DST that are coupled toeach of the memory strings String may be two or more without beinglimited to one.

The memory strings String may be arranged in a matrix form in a rowdirection and a column direction. The memory strings String may becoupled on a column basis to the bit lines BL1 to BL5 extending in thecolumn direction. The memory strings String may be coupled on a rowbasis to gate lines SSL, WL1 to WLn and DSL extending in the rowdirection.

The source select transistor SST, the plurality of memory celltransistors MC1 to MCn, and the drain select transistor DST may becoupled in series to each other by the channel layer and form a singlememory string String. The memory strings String may be disposed betweenthe bit lines BL1 to BL5 and first and second source lines SL1 and SL2.The gate lines SSL, WL1 to WLn and DSL are stacked between the bit linesBL1 to BL5 and the first and second source lines SL1 to SL2, and arespaced apart from each other.

The gate lines may include a source select line SSL, word lines WL1 toWLn and a drain select line DSL. The source select line SSL is used as agate electrode of the source select transistor SST. The word lines WL1to WLn are used as gate electrodes of the memory cell transistors MC1 toMCn. The drain select line DSL is used as a gate electrode of the drainselect transistor DST. The word lines WL1 to WLn are stacked and spacedapart from each other. The source select line SSL is disposed below theword lines WL1 to WLn. The drain select line DSL is disposed over theword lines WL1 to WLn. In other words, the word lines WL1 to WLn aredisposed between the source select line SSL and the drain select lineDSL.

The first source line SL1 and the second source line SL2 are disposedbelow the source select line SSL, and are coupled in parallel to thesource select transistors SST of the memory strings String. Each of thebit lines BL1 to BL5 is coupled to the drain select transistor DST ofthe corresponding memory string String.

The memory strings String coupled in common to a single drain selectline DSL are coupled to different bit lines BL1 to BL5. Therefore, whenone drain select line DSL is selected and one of the bit lines BL1 toBL5 is selected, one of the memory strings String may be selected.

The first source line SL1 and the second source line SL2 arerespectively electrically coupled to a first common source line CSL1 anda second common source line CSL2. During an erase operation of thesemiconductor device, when an erase voltage is applied to the firstcommon source line CSL1, the erase voltage is applied to the channellayers of the memory strings String through the first source line SL1.Furthermore, during a program verify operation or a read operation ofthe semiconductor device, when an operating voltage (e.g., a groundvoltage) is applied to the second common source line CSL2, a path ofcurrent flowing from the channel layers of the memory strings String tothe second source line SL2 and the second common source line CSL2 may beformed.

During the erase operation of the semiconductor device, the secondsource line SL2 and the second common source line CSL2 remain floating,and during the program verify operation or the read operation of thesemiconductor device, the first source line SL1 and the first commonsource line CSL1 remain floating.

Whether the channel layer of each memory string String is electricallycoupled to the first source line SL1 or the second source line SL2 maybe determined depending on a signal to be applied to the source selectline SSL.

During a program verify operation of the semiconductor device, thepotentials of the channel layers of the memory strings String areprecharged to a predetermined level through the bit lines BL1 to BL5,and an operating voltage (e.g., a ground voltage) is applied to thesecond common source line CSL2 and the second source line SL2.Thereafter, when a program verify voltage is applied to a selected wordline of the word lines WL1 to WLn, and a pass voltage is applied to theother word lines, the memory cells coupled with the selected word lineare turned on or off depending on a program state thereof. Consequently,the potential of the channel layer of each memory string String ismaintained at a predetermined level, or is discharged to a low level bythe path of current flowing through the second source line SL2 and thesecond common source line CSL2. Thereafter, the program verify operationis performed by measuring the potential levels or current of the bitlines BL1 to BL5.

During an erase verify operation, the potentials of the channel layersof the memory strings String are precharged to a predetermined levelthrough the bit lines BL1 to BL5, and an operating voltage (e.g., aground voltage) is applied to the second common source line CSL2 and thesecond source line SL2. Thereafter, when an erase verify voltage isapplied to all of the word lines WL1 to WLn, the memory cells MC1 to MCncoupled to the word lines WL1 to WLn are turned on or at least onememory cell is turned off, depending on erase states of the memory cellsMC1 to MCn. Consequently, the potential of the channel layer of eachmemory string String is maintained at a predetermined level, or isdischarged to a low level by the path of current flowing through thesecond source line SL2 and the second common source line CSL2.Thereafter, the erase verify operation is performed by measuring thepotential levels or current of the bit lines BL1 to BL5.

In the above description, the erase verify operation has been describedas being simultaneously performed on the memory cells MC1 to MCnincluded in the memory strings String, but the present disclosure is notlimited thereto. For example, in the same manner as that of the programverify operation, an erase verify voltage may be applied to a selectedword line, and a pass voltage may be applied to the other word lines sothat the erase verify operation may be performed on each of the memorycells MC1 to MCn.

During a read operation of the semiconductor device, the potentials ofthe channel layers of the memory strings String are precharged to apredetermined level through the bit lines BL1 to BL5, and an operatingvoltage (e.g., a ground voltage) is applied to the second common sourceline CSL2 and the second source line SL2. Thereafter, when a readvoltage is applied to a selected word line of the word lines WL1 to WLn,and a pass voltage is applied to the other word lines, the memory cellscoupled with the selected word line are turned on or off depending on aprogram state thereof. Consequently, the potential of the channel layerof each memory string String is maintained at a predetermined level, oris discharged to a low level by the path of current flowing through thesecond source line SL2 and the second common source line CSL2.Thereafter, the read operation is performed by measuring the potentiallevels or current of the bit lines BL1 to BL5.

During an erase operation, a voltage having a predetermined level isapplied to the bit lines BL1 to BL5, and a turn-off voltage is appliedto the drain select line DSL to turn off the drain select transistorDST, whereby the electrical coupling of the bit lines BL1 to BL5 to thememory strings String is interrupted.

Thereafter, while the word lines WL1 to WLn are floating, an erasevoltage is applied to the first common source line CSL1 and the firstsource line SL1, and a turn-on voltage is applied to the source selectline SSL to turn on the source select transistor SST so that the erasevoltage is applied to the channel layers of the memory strings String.Thereafter, when a ground voltage is applied to the word lines WL1 toWLn, electrons charged in the memory cells MC1 to MCn are detrapped bydifference in potential level between the channel layers and the wordlines WL1 to WLn. Consequently, data programmed in the memory cells MC1to MCn is erased.

As described above, in an embodiment of the present disclosure, during aprogram verify operation, an erase verify operation or a read operation,a current path is formed through the second common source line CSL2 andthe second source line 51_2. During an erase operation, an erase voltageis applied to the channel layers of the memory strings through the firstcommon source line CSL1 and the first source line SL1. As describedabove, a source line is divided into the first source line SL1 and thesecond source line SL2 that are electrically and physically separatedfrom each other. Therefore, the second source line SL2 for a programverify operation, an erase verify operation or a read operation may beformed of an N-type conductive layer, and the first source line SL1 foran erase operation may be formed of a P-type conductive layer, so thatelectrical characteristics of each operation may be improved.

FIGS. 3A to 3H are sectional views illustrating a method ofmanufacturing a semiconductor device according to an embodiment of thepresent disclosure.

Referring to FIG. 3A, a first stack structure A for forming a sourceline is formed on a substrate (not illustrated) including a lowerstructure.

For example, a first conductive layer 101, a separation layer 103, afirst buffer layer 105, a sacrificial layer 107, a second buffer layer109 and an etch stop layer 111 are successively stacked and formed onthe substrate (not illustrated) including the lower structure.

The first conductive layer 101 may be a conductive layer for forming thefirst source line SL1 illustrated in FIG. 1, and be formed of a dopedpolysilicon layer. The separation layer 103 may be an insulating layerfor electrically and physically separating the first conductive layer101 from a second source line SL2 to be formed later, and be formed of asilicon oxide layer. The first buffer layer 105 may be a layer forpreventing the separation layer 103 from being etched during asubsequent etching process, and be formed of a nitride layer. Thesacrificial layer 107 may be a layer to secure a space for forming thesecond source line SL2 to be formed later, and be formed of an undopedpoly layer. The second buffer layer 109 may be a layer for preventingthe etch stop layer 111 from being damaged during a process of etching amultilayer layer on a sidewall of a channel to be formed later, and beformed of a silicon oxide layer.

Thereafter, a second stack structure B is formed on the first stackstructure A.

For example, first material layers 113 and second material layers 115are alternately stacked on the etch stop layer 111. The second materiallayers 115 may be formed of material different from that of the firstmaterial layers 113. For example, the first material layers 113 may beformed of insulating material for interlayer insulating layers, whereasthe second material layers 115 may be formed of conductive material forconductive patterns.

Alternatively, the first material layers 113 may be formed of insulatingmaterial for interlayer insulating layers, and the second materiallayers 115 may be used as sacrificial layers and be formed ofsacrificial insulating material having an etching selectivity differentfrom that of the first material layers 113. In this case, the firstmaterial layers 113 may be formed of a silicon oxide layer, and thesecond material layers 115 may be formed of a silicon nitride layer. Inthe case where all of the first and second material layers 113 and 115are formed of insulating material, etching processes for forming achannel hole or a slit may be facilitated.

Alternately, the first material layers 113 may be used as sacrificiallayers and be formed of sacrificial conductive material having anetching selectivity different from that of the second material layers115, whereas the second material layers 115 may be formed of conductivematerial for conductive patterns. In this case, the first materiallayers 113 may be formed of an undoped polysilicon layer, whereas thesecond material layers 115 may be formed of a doped polysilicon layer.In the case where all of the first and second material layers 113 and115 are formed of conductive material, etching processes for forming achannel hole or a slit may be facilitated.

Referring to FIG. 3B, channel holes H1 and H2 passing through portionsof the second stack structure B and the first stack structure A areformed. Each of the channel holes H1 and H2 may be formed such thatportions of an upper surface of the first conductive layer 101 areexposed.

Thereafter, a multilayer layer ML and a channel layer 123 aresequentially formed along a sidewall and the bottom of each of thechannel holes H1 and H2.

The multilayer layer ML may be formed by successively stacking a tunnelinsulating layer 117, a data storage layer 119 and a blocking insulatinglayer 121. Thereafter, the channel layer 123 may be formed along thesurface of the blocking insulating layer 121. The blocking insulatinglayer 121, the data storage layer 119, the tunnel insulating layer 117may be formed to enclose the channel layer 123. The channel layer 123may be formed such that a central region of each of the channel holes H1and H2 is open.

The tunnel insulating layer 117 may be formed of an oxide layer. Thedata storage layer 119 may be formed of a nitride layer. The blockinginsulating layer 121 may be formed of an oxide layer. The multilayerlayer ML may be formed of an ONO structure (an oxide layer—a nitridelayer—an oxide layer). Furthermore, each of oxide layers of themultilayer layer ML may be formed of a single oxide layer, or be formedof a structure in which different material layers including an oxidelayer are stacked.

Referring to FIG. 3C, the channel layer 123 and the multilayer layer MLthat are formed on the bottom of each of the channel holes H1 and H2 areremoved through an etching process, whereby the first conductive layer101 is exposed. Thereafter, an additional channel layer 123 is formed onthe exposed first conductive layer 101 so that the channel layer 123 iselectrically and physically coupled to the first conductive layer 101.

Thereafter, the central region of each of the opened channel holes H1and H2 may be filled with a core insulating layer 125. As a result,channel plugs CP each of which are configured with the core insulatinglayer 125, the channel layer 123 and the multilayer layer ML are formed.

Referring to FIG. 3D, a second source contact hole H3 is formed throughan etching process. The second source contact hole H3 is formed to passthrough the second stack structure B, the etch stop layer 111 and thesecond buffer layer 109 and expose the sacrificial layer 107.

Thereafter, the exposed sacrificial layer 107 is removed to form a spacein which a conductive layer for a second source line is to be formed.When the sacrificial layer 107 is removed, a lower portion of thesidewall of each channel plug CP is exposed. In other words, a lowerportion of the tunnel insulating layer 117 of the channel plug CP isexposed.

Referring to FIG. 3E, the exposed portions of the tunnel insulatinglayer 117, the data storage layer 119 and the blocking insulating layer121 are removed through an etching process, whereby a portion of thechannel layer 123 is exposed. During a process of etching the tunnelinsulating layer 117, the second buffer layer 109 may be removed, andduring a process of etching the data storage layer 119, the first bufferlayer 105 may be removed. Here, the tunnel insulating layer 117, thedata storage layer 119 and the blocking insulating layer 121 may befurther etched upward from the exposed portions thereof. Consequently,the tunnel insulating layer 117, the data storage layer 119 and theblocking insulating layer 121 may be etched to a position higher thanthe space that is formed by removing the sacrificial layer 107 asdescribed in FIG. 3D. Therefore, the space in which the conductive layerfor the second source line is to be formed may protrude a predeterminedheight upward at a position at which the space comes into contact withthe channel layer 123.

Referring to FIG. 3F, a second conductive layer 127 for the secondsource line is formed in the space from which the sacrificial layer hasbeen removed. The second conductive layer 127 may be formed of anundoped polysilicon layer or a polysilicon layer doped with an N-typeimpurity. The second conductive layer 127 is electrically and physicallycoupled with the channel layer 123. The portion of the second conductivelayer 127 that comes into contact with the channel layer 123 mayprotrude a predetermined height upward. For example, the thickness ofthe portion of the second conductive layer 127 that comes into contactwith the channel layer 123 may be greater than that of the portion ofthe second conductive layer 127 that is formed between the separationlayer 103 and the etch stop layer 111. In an embodiment, for example, athickness of a region of the auxiliary source line layer SL2 that comesinto contact with each of the channel layers 123 is greater than athickness of the other regions of the auxiliary source line layer SL2.In an embodiment, for example, a thickness of a region of the auxiliarysource line layer SL2 between the first multilayer pattern ML1 and thesecond multilayer pattern ML2 is greater than a thickness of theauxiliary source line layer SL2 outside the region between the firstmultilayer pattern ML1 and the second multilayer pattern ML2. In anembodiment, for example, a thickness of a region of the auxiliary sourceline layer SL2 between the etch stop layer 11 and the separation layer103 may be narrower than a thickness of a region of the auxiliary sourceline layer SL2 between the first multilayer pattern ML1 and the secondmultilayer pattern ML2. In an embodiment, for example, a thickness of aregion of the auxiliary source line layer SL2 between the etch stoplayer 11 and the separation layer 103 may be narrower than a thicknessof a region of the auxiliary source line layer SL2 that comes intocontact with each of the channel layers 123.

Thereafter, an insulating layer 129 is formed on the sidewall of thesecond source contact hole H3, and the second source contact hole H3 isfilled with a conductive layer to form a second source contact plug 131.

Referring to FIG. 3G, a first source contact hole H4 is formed throughan etching process. The first source contact hole H4 is formed to passthrough the second stack structure B, the etch stop layer 111 and thesecond conductive layer 127 and expose a portion of the first conductivelayer 101. The first source contact hole H4 may be formed such that aportion of the first conductive layer 101 is etched.

Thereafter, an insulating layer 133 is formed on the sidewall of thefirst source contact hole H4, and the first source contact hole H4 isfilled with a conductive layer to form a first source contact plug 135.The first source contact plug 135 may extend into the first conductivelayer 101 by a predetermined depth. In other words, the first sourcecontact plug 135 may pass through a predetermined thickness of the firstconductive layer 101.

Referring to FIG. 3H, a slit SI is formed to pass through the first andsecond material layers 113 and 115 by etching a portion of the first andsecond material layers 113 and 115 between the channel plugs CP. Duringan etching process for forming the slit SI, due to the etch stop layer111, the second conductive layer 127 disposed under the etch stop layer111 is prevented from being damaged.

Thereafter, the slit SI is filled with insulating material to form aslit insulating layer 137.

In the case where the first material layers 113 are formed of insulatingmaterial for interlayer insulating layers and the second material layers115 are formed of sacrificial insulating material, before the slitinsulating layer 137 is formed after the slit SI has been formed, thesecond material layers 115 may be selectively removed through the slitSI to open conductive pattern regions, and then conductive patterns maybe formed by filling the conductive pattern regions with conductivematerial.

FIG. 4 is a block diagram illustrating a memory system 1000 including asemiconductor memory device 100 in accordance with an embodiment of thepresent disclosure.

Referring to FIG. 4, the memory system 1000 includes a controller 1100and a semiconductor memory device 100. The semiconductor memory device100 may include the semiconductor devices described with reference toFIGS. 1 and 2, and may employ the semiconductor devices realized by themethods of manufacturing the semiconductor devices described withreference to FIGS. 3A to 3H.

The semiconductor memory device 100 may include and operate a memorycell array including the memory strings described with reference toFIGS. 1 and 2. Consequently, the memory strings of the memory cell arrayincluded in the semiconductor memory device 100 are coupled in parallelto the first source line and the second source line. An erase voltagemay be applied to the first source line during an erase operation. Anoperating voltage (e.g., a ground voltage) may be applied to the secondsource line during a program verify operation, an erase verify operationor a read operation. Hereinafter, repetitive explanations will beomitted.

The controller 1100 may be coupled to a host Host and the semiconductormemory device 100. The controller 1100 is configured to access thesemiconductor memory device 100 in response to a request from the hostHost. For example, the controller 1100 may control read, write, erase,and background operations of the semiconductor memory device 100. Thecontroller 1100 may provide an interface between the host Host and thesemiconductor memory device 100. The controller 1100 is configured todrive firmware for controlling the semiconductor memory device 100.

The controller 1100 includes a random access memory (RAM) 1110, aprocessing unit 1120, a host interface 1130, a memory interface 1140,and an error correction block 1150. The RAM 1110 is used as at least oneof an operation memory of the processing unit 1120, a cache memorybetween the semiconductor memory device 100 and the host Host, and abuffer memory between the semiconductor memory device 100 and the hostHost.

The host interface 1130 may include a protocol for performing dataexchange between the host Host and the controller 1100. In an example ofan embodiment, the controller 1100 may communicate with the host Hostthrough at least one of various interface protocols such as a universalserial bus (USB) protocol, a multimedia card (MMC) protocol, aperipheral component interconnection (PCI) protocol, a PCI-express(PCI-E) protocol, an advanced technology attachment (ATA) protocol, aserial-ATA protocol, a parallel-ATA protocol, a small computer smallinterface (SCSI) protocol, an enhanced small disk interface (ESDI)protocol, and an integrated drive electronics (IDE) protocol, a privateprotocol, and the like.

The memory interface 1140 interfaces with the semiconductor memorydevice 100. For example, the memory interface includes a NAND interfaceor a NOR interface.

The error correction block 1150 uses an error correcting code (ECC) todetect and correct an error in data received from the semiconductormemory device 100. The processing unit 1120 may adjust the read voltageaccording to an error detection result from the error correction block1150, and control the semiconductor memory device 100 to performre-reading. In an example of an embodiment, the error correction block1150 may be provided as an element of the controller 1100.

The controller 1100 and the semiconductor memory device 100 may beintegrated into a single semiconductor device. In an example of anembodiment, the controller 1100 and the semiconductor memory device 100may be integrated into a single semiconductor device to form a memorycard. For example, the controller 1100 and the semiconductor memorydevice 100 may be integrated into a single semiconductor device and forma memory card such as a personal computer memory card internationalassociation (PCMCIA), a compact flash card (CF), a smart media card (SMor SMC), a memory stick multimedia card (MMC, RS-MMC, or MMCmicro), a SDcard (SD, miniSD, microSD, or SDHC), a universal flash storage (UFS),and the like.

The controller 1100 and the semiconductor memory device 100 may beintegrated into a single semiconductor device to form a solid statedrive (SSD). The SSD includes a storage device formed to store data in asemiconductor memory. When the memory system 1000 is used as the SSD, anoperation speed of the host Host coupled to the memory system 1000 maybe phenomenally improved.

In an embodiment, the memory system 1000 may be provided as one ofvarious elements of an electronic device such as a computer, a ultramobile PC (UMPC), a workstation, a net-book, a personal digitalassistants (PDA), a portable computer, a web tablet, a wireless phone, amobile phone, a smart phone, an e-book, a portable multimedia player(PMP), a game console, a navigation device, a black box, a digitalcamera, a 3-dimensional television, a digital audio recorder, a digitalaudio player, a digital picture recorder, a digital picture player, adigital video recorder, a digital video player, a device capable oftransmitting/receiving information in an wireless environment, one ofvarious devices for forming a home network, one of various electronicdevices for forming a computer network, one of various electronicdevices for forming a telematics network, an RFID device, one of variouselements for forming a computing system, or the like.

In an embodiment, the semiconductor memory device 100 or the memorysystem 1000 may be embedded in various types of packages. For example,the semiconductor memory device 100 or the memory system 1000 may bepackaged in a type such as Package on Package (PoP), Ball grid arrays(BGAs), Chip scale packages (CSPs), Plastic Leaded Chip Carrier (PLCC),Plastic Dual In Line Package (PDIP), Die in Waffle Pack, Die in WaferForm, Chip On Board (COB), Ceramic Dual In Line Package (CERDIP),Plastic Metric Quad Flat Pack (MQFP), Thin Quad Flatpack (TQFP), SmallOutline (SOIC), Shrink Small Outline Package (SSOP), Thin Small Outline(TSOP), Thin Quad Flatpack (TQFP), System In Package (SIP), Multi ChipPackage (MCP), Wafer-level Fabricated Package (WFP), Wafer-LevelProcessed Stack Package (WSP), or the like.

FIG. 5 is a block diagram illustrating an example of application of thememory system of FIG. 4. Referring FIG. 5, a memory system 2000 includessemiconductor devices 2100 and a controller 2200. The semiconductormemory device 2100 may include a plurality of memory chips. Thesemiconductor memory chips are divided into a plurality of groups.

In FIG. 5, it is illustrated that each of the plurality of groupscommunicates with the controller 2200 through first to k-th channels CH1to CHk. Each semiconductor memory chip may include the memory stringsdescribed with reference to FIGS. 1 and 2, and the memory cell arrayincluding the memory strings. Each semiconductor memory chip may includethe semiconductor devices described with reference to FIGS. 1 and 2, andmay employ the semiconductor devices realized by the methods ofmanufacturing the semiconductor devices described with reference toFIGS. 3A to 3H.

Each group communicates with the controller 2200 through one commonchannel. The controller 2200 has the same configuration as that of thecontroller 1100 described with reference to FIG. 4 and is configured tocontrol a plurality of memory chips of the semiconductor memory device2100 through the plurality of channels CH1 to CHk.

FIG. 6 is a block diagram illustrating a computing system 3000 includingthe memory system 2000 illustrated with reference to FIG. 5.

Referring to FIG. 6, the computing system 3000 may include a centralprocessing unit 3100, a RAM 3200, a user interface 3300, a power supply3400, a system bus 3500, and a memory system 2000.

The memory system 2000 is electrically coupled to the CPU 3100, the RAM3200, the user interface 3300, and the power supply 3400 through thesystem bus 3500. Data provided through the user interface 3300 orprocessed by the CPU 3100 is stored in the memory system 2000.

Referring to FIG. 6, the semiconductor memory device 2100 is illustratedas being coupled to the system bus 3500 through the controller 2200.However, the semiconductor memory device 2100 may be directly coupled tothe system bus 3500. The function of the controller 2200 may beperformed by the CPU 3100 and the RAM 3200.

Referring to FIG. 6, the memory system 2000 described with reference toFIG. 5 may be provided. However, the memory system 2000 may be replacedwith the memory system 1000 described with reference to FIG. 4. In anembodiment, the computing system 3000 may include all of the memorysystems 1000 and 2000 described with reference to FIGS. 4 and 5.

In a three-dimensional semiconductor device according to the techniqueof the present disclosure, a source line coupled to memory strings isdivided into a source line for a program operation or a read operationand a source line for an erase operation, so that electricalcharacteristics of each operation may be improved.

Examples of embodiments have been disclosed herein, and althoughspecific terms are employed, they are used and are to be interpreted ina generic and descriptive sense only and not for purpose of limitation.In some instances, as would be apparent to one of ordinary skill in theart as of the filing of the present application, features,characteristics, and/or elements described in connection with aparticular embodiment may be used singly or in combination withfeatures, characteristics, and/or elements described in connection withother embodiments unless otherwise specifically indicated. Accordingly,it will be understood by those of skill in the art that various changesin form and details may be made without departing from the spirit andscope of the present disclosure as set forth in the following claims.

What is claimed is:
 1. A semiconductor device comprising: a memorystring including memory cells coupled to each other in series via achannel layer, the memory string coupled between a bit line and a secondsource line; and a first source line electrically coupled to the secondsource line through the channel layer.
 2. The semiconductor deviceaccording to claim 1, wherein the first source line is a P-typeconductive layer, and the second source line is an N-type conductivelayer.
 3. The semiconductor device according to claim 1, furthercomprising: a first common source line coupled to the first source line;and a second common source line coupled to the second source line. 4.The semiconductor device according to claim 3, further comprising:wherein during a read operation of a memory cell within the memorystring a current path is formed through the second common source lineand the second source line, and wherein during an erase operation, anerase voltage is applied to the channel layer of the memory stringthrough the first common source line and the first source line.
 5. Thesemiconductor device according to claim 4, wherein during a programverify operation and an erase verify operation of a memory cell withinthe memory string a current path is formed through the second commonsource line and the second source line.
 6. The semiconductor deviceaccording to claim 1, further comprising: a separation layer coupledbetween the second source line and a first source line.
 7. Thesemiconductor device according to claim 6, wherein the separation layercoupled between the second source line and the first source lineelectrically and physically separates the second source line from thefirst source line.